Modeling and simulation of high efficiency eco-friendly perovskite-CZTSe$_{1-x}$S$_x$ solar cell

In the present paper, a Pb-free and eco-friendly perovskite solar cell (PSC) with a new structure of glass|TCO|TiO$_2$|CZTSe$_{1-x}$S$_x$|CH$_3$NH$_3$SnI$_3$|back contact has been modeled and simulated by SCAPS-1D package. To verify the simulation process, an experimental report on Pb-free PSC was simulated initially. Then, the costly Spiro-OMeTAD layer as the common hole-transport material (HTM) was eliminated. To overcome the possible deficiencies related to lacking of HTM plus management of the incident light, the economic and eco-friendly Cu$_2$ZnSn(Se$_{1-x}$S$_x$)$_4$ (CZTSe$_{1-x}$S$_x$) layer was added in the front of perovskite layer followed by optimizing the parameters. By optimization, the power-conversion efficiency of 17.57%, open-circuit voltage Voc of 0.85 V, short-circuit current density Jsc of 29.22 mA/cm$^2$, and fill factor of 70.47% were obtained. Meanwhile, very high quantum efficiency was achieved in the visible region of spectrum.